The invention relates to a syringe which will accomplish the sequential injection of at least two volumes of liquid with a minimal amount of mixing prior to and during injection.
In the prior art, the injection of specific volumes of two medicaments could be accomplished without substantial intermixing if two syringe assemblies were used. This could be inconvenient for both doctor and patient, and time consuming. Multiple compartment syringes are known to the art, but most of these are designed to mix their separated components prior to or during injection. Valves or plugs with puncture means are often used to separate the chambers thus complicating the structure and operation of these devices.
The injection of radioisotopes into a patient for diagnostic or therapeutic purposes may also present problems. Once the injection has been made, it is desirable to remove the residual radioactive contents from the syringes simply so as to avoid contamination. If a conventional syringe is used, it must be refilled and then injected in order to flush the contents from the device. Once the empty syringe is placed down after use, it would be easy to forget to remove the radioactive material. However, if another liquid is already present in the syringe for this purpose, it would remind the doctor or technician to flush the device and provide an efficient means for doing so.